apartment therapy changing the world, one room at a time

I tend to organize my books by genre, then by series - ex. "Dragonriders of Pern" or J.D. Robb's "in Death" series, and will try to keep all books by one author together, but not necessarily in alphabetical order. It's more"where will it/they fit in the space I have?"

I absolutely love that bookcase in the picture!! Wish I had a few.

By topic -- art books together, poetry all in one place, reference books on the same shelf, etc.

By category: reference and keepers; next books to read; classics to read; and mystery, detective, and other absorbing but light books to read.

On the various books to read shelves, books are grouped by series, where relevant (such as the Faulkners, in order), and are arranged from left to right in the order I think I might want to read them next, subject to revision.

I also have stacks of various self-help, financial, home design and organization, and other such books stacked up randomly, in the order that I put them down, intending to get back to them at some point.

When I finish reading a book, if it's not a keeper (keepers are usually reference or sentimental, occasionally for some other reason), I put it in an "out" bag in the front closet for giving/swapping to friends or for taking in to used bookstores for trade or donation.

by subject!

Maybe this is an age thing, but in the day of the internet, I don't have many books. Still being in school, I read so much that I don't care to pick up a novel at the moment. I do love the look of books though, might buy some more just to decorate with haha. It's just the internet is so much easier and current. Video killed the radio star...

Library of Congress #

I'm with Garret. Wikipedia, eBooks and all the media, manuals, tutorials, recipes... are too much to keep up with books. I just get the abridged blog version and do a quick search for pictures or references. I've magazines, of which I mostly keep pictures of and then dispose of. Life's too short and space too valuable to share it with "soon-to-be-obsolete" info.

I like to arrange via color. In my opinion it looks neater, and it's surprisingly easy to find what I'm looking for.

I do clump all my cookbooks together, though.

I arrange books by subject. For example; all travel books are together. This is the same for novels and other books of fiction, biographies, cook books, music texts, programing/scripting books etc...

Generally, people who organize books by color baffle me. How impractical. Do these people even refer to their library?

I do understand why people organize their books by color. It does look nice. Still, sometimes I wonder why they don't just throw a rainbow up on their wall.

aaah! Garrett and djlucky are going to give me a heart attack! I LOVE keeping tons and tons of books around. Not so much that they make my space too full, but enough that the ones I really love are always at hand. My parents just recently made me throw out half of the books I keep at their house (ummm....oops?) and I was practically in tears trying to decide between them!

"Generally, people who organize books by color baffle me."

I guess if you only have a few dozen, you'd remember... the thick blue book... instead of it's exact real name.

Ditto -- by subject. And only reference books, like cookbooks, gardening books, etc. I don't keep novels. Read 'em and pass 'em on.

First I do it by general size, then within that I do it by topic or theme. Fortunately most books of similar type tend to have the same shapes and sizes--ie photography books tend to be tall and quality softback novels tend to be medium sized, etc.

I agree with Casandra. Arranging books by color looks contrived and impractical. Talk about putting form above function!

In my house, we have all of the fiction books arranged alphabetically by author's name so that certain book series can be together. My cookbooks are not kept with the other books and, I must admit, they're just stacked up randomly in a cabinet in the kitchen. I only have 5 or 6, though, so it isn't an issue.

I have my loosely grouped by author and series, with the hardcovers in plain sight and the paperbacks relegated to the bookcase in the kitchen. The cookbooks are on the shelf above the sink.

by category (such as fiction) then in sections: already read, to be read, and flipped through , but not read yet.

oh, and also by size.

I organize them a little by size and in groups that look good together on the self. While it's not the most organized way to find something, it looks the best. I don't have that many so it's not hard to find what I'm looking for.

I have two different floor to ceiling bookshelves in my place. In my office I have the books I need to work on my dissertation. Those books are arranged by historical figure/historical era (I work in classics). In each era, I first have the primary sources in the original text, then the primary sources in translation, and then finally the secondary sources that relate to the primary texts. (It's a clear sign that I'm working on my dissertation that my bookshelf is in perfect order. I find any excuse what so ever to do things other than what I should be doing -- writing!)

In my bedroom I have my fiction. I tend to arrange these by types of literature. One shelf is full of anthologies of short stories, another has what I consider 'high fiction' (all those classics that I tell myself I need to read!), another shelf for my 'low fiction' (Harry Potter, etc), and then a shelf of things that don't fit elsewhere.

I gave away a lot of my books, only keeping the ones that I am sure I will reference again, or I think won't be available in the public library system. And except for the cookbooks and several coffee table books, the rest are kept in a trunk I rarely open, unorganized.
Tha magazines are grouped together in cheapie magaine boxes that I am hoping to upgrade via a trip to Ikea.
Coffee table book that is a big hit with guests - Transit Maps of the World by Mark Ovenden and Mike Ashworth.

also by subject.

i organize books by one topic per shelf, then color code the books on that shelf. fiction, nonfiction (general), nonfiction (art theory), photo instruction, coffee table books, magazines.

I'm pretty strict about purging my shelves of books I know I won't re-read or refer to ever again, but I'm a pretty avid reader (and re-reader), which means I still have four floor-to-ceiling bookcases in my home. And that's not even considering the kids' books...

Some of my organizational scheme is obvious: cookbooks, design books, etc. But at least three quarters of my books are fiction, which I organize by my own personalized system: an arcane combination of alphabetic and thematic.

For example, it's obvious (to me, anyway) that the novels of Sherwood Anderson and John O'Hara need to be alongside Ernest Hemingway, F. Scott Fitzgerald, and Gertrude Stein. It's just as obvious that The Diary of Anne Frank needs to be next to Anne Michaels' novel Fugitive Pieces. And Louis de Berniere's novels should be next to Annie Proulx's because, despite the fact that they're opposites in many ways, I suspect they would really like each other if they met in real life.

I call it the Doppelganger Decimal System. My favourite thing about it is that I'm the only person in the world who knows it.

I keep a basket of slippers in my entry (next to a chair for taking off shoes), but in Montreal lots of people travel with their own slippers.

I've never had to ask anyone to remove shoes. The see that I'm in stocking feet and they see several pairs of shoes lined up by the door, and they get it. No need for a "Shoes Off" sign (which seems kinda obnoxious to me).

We have a few thousand books, so I organize them by subject with a section for fiction. Within the nonfiction, I arrange by author; within fiction, I arrange by author, then title for multiple works by the same author. I have over 100 cookbooks, so I arrange them by type (quick, dessert, vegetarian).

Like Casandra, I too have always found an arrangement by color to be baffling. However, just today, I saw something even more baffling: the March issue of Country Home shows a library where the homeowner placed all the books backwards (spines facing the wall) on the shelves so the bookcase wouldn't be a "distracting jumble."

I group them by type, then by size. I have them in several areas around the house - some are stacked horizontally, others are displayed traditionally in a glass front case. I tend to keep only the hardcover books - paperbacks bore me.

totally hodgepodge except for my livingroom/bedroom shelves. they're hodgepodge by subject but only sort of delineated by color. the whiter ones are the closest to the ceiling to create the look of receding.

hodgepodge isn't so much a problem i guess since i only have these categories: art, spirit/philosophy, psychology, cooking, and native american with just a few poetry books in the mix. anything else i usually just refer to the internet about.

Two steps, the first for practicality and the second for aesthetics. The books are all organized by subject (poetry, fiction, philosophy), but within those categories I just tried to make the arrangement look attractive, without worrying about alphabetizing.

Most of our books are on back-to-back bookcases that form a divider between the living and dining areas. They're arranged by color and size, thusly:

http://www.flickr.com/photos/visualingual/2098637661/in/set-72157594505190197/

The rest, which are currently in some sort of use, are arranged haphazardly in the studi area. The color/size arrangement was maddening at first, but we quickly started to remember heights and spine colors. Plus, it looks pretty, and we don't need those books every day.

I group them by genre, then author, and series. I put my favorite groups on the shelves that are easiest to see and reach.

Actually... a good number of my favorite reads are scattered around the house with bookmarks in all of them. I'm always in the middle of a couple books.

Library of Congress.

"Generally, people who organize books by color baffle me. How impractical. Do these people even refer to their library?"

Um, I bet I have more books than most people and yes, I can find everything very easily. I works for me, and that's what counts.

I group and use my books like AnnadyL above.. my books are workhorses right now- I'd love the luxury of sorting by color but the retrieval process would be too hard.

I have them arranged by size because of my limited space. The shelves are adjusted to give maximum space. So all paperbacks are on one shelf, tall books on another, normal hardbacks on another etc. I do try to categorize them to make sense, but first and foremost is fitting them all in the shelves.

I did like the color arrangement but wouldn't do it because it didn't make sense to me (how would you find anything). I did end up taking all the covers off my hardback books though because I thought the plain spine looked nicer then the random cover art.

By theme.

I try to put them by subject. I place some of them vertically and some horizontal. I place my travel mementos on top of the horizontal books to add interest and color.

I don't keep many fiction books, other than those I know I will want to reread at some point. My collection is largely non-fiction and sorted by subject. Within subject, it is sorted by size.

In all nine floor to ceiling bookcases.

I love that 2 people said LCC. That's just awesome.
It turns out I'm too lazy to actually do that though, so it's fiction by author and then non-fiction broken into subjects, and then arranged by author or whatever makes sense to me.

by genre, then by size/attractive shelf arrangement.

by genre first, then by author (fiction, biography) or by size (manual, cookbooks, etc.) or by subject (text books)

By size - they wouldn't fit on the shelves if I didn't make the absolute best use of vertical space possible.

color & subject.

i did mine by color this past weekend, and i've got to say it looks great. We don't keep a huge amount of books here and the small bookcase looks great arranged by color.

To the people that thinks it's impractical, why, because it doesn't work for you? I think doing books by dewey or the library of congress, is impractical, but that doesn't make it wrong.

it is completely different then putting a rainbow on your wall....

and I'm going to go into a Seinfeld reference here. what is people's fascination with books. why do they want to keep so many? People use their bookcase like a trophy case. look at how many book i own, look how smart i am, i've read all of these (yes...all of these!), I'm amazing!

The books that I have here are either graphic design which i keep close by for reference since it's what i do, and the others because I'm sure i'll reference them often or i know i'll read it again because it's my favorite author. I don't see the point in keeping thousands of books unless it's what you do, if you're really into books, librarians, english professors, journalists, etc. But i doubt all of you are...

When people arrange their books by color I think it looks like they don't actually read them, they just want them as a prop.

Fiction is in the bedroom bookcase organized by size, books by the same author grouped together.

Nonfiction is in the living room grouped by subject area (decorating, religion, crafts or cooking, and other).

By subject. Literature is arranged by chronology and then alphabetically within the period. Other categories (history, garden, cookbooks, music, travel, cinema) just by subject and the size of the shelf. Rarer and older books go in their own glass bookshelf. Of course there are other strategic stacks of books to read right away or that one is in the process of reading. Then there is the "read and discard" pile. These go on tables. On desks, and on the floor.

I notice the poll doesn't have by subject as a category. Weird. Arrangement by color not practical, unless you never intend to open the book and read it.

By subject/genre (history, travel, organizing, mysteries, etc.) and then somewhat by size. I also keep series together.

Books are by topic, but it's how we see the topics going together, as Library of Congress is too detailed for our modest number of books, and once you're used to LCC, Dewey seems like using those big kindergarten crayons.

Doing any work where you need to compare multiple translations -- or a translation against an untranslated original -- is so much more complicated if you've separated the otherwise identical texts based on their spine colors!

Hodgepodge. Oh no wait. I have the cookbooks separated out and near the kitchen but otherwise my books all just go into the shelves however. Oh no wait. The smaller ones i stack horizontally, so maybe there's a touch of arranging by size going on. Then again, I usually put the ones I don't care for that much on the bottom shelves--is there an "arrange by preference" category?

By subject, and then by size (just to keep the shelves from looking too random/disorganised).

I try to arrange books by subject and then by size. Although I do have have some places in my apartment where I have books in the same color regardless of subject.

By subject! Duh!

I actually use all my books so they are arranged by subject matter first, height second and colour third.

By subject matter. The trend to arrange by color annoys me to no end.

--the tempermental literary agent

Autobiographically. Laura Ingalls Wilder and the first edition picture books on the top, angsty high school fiction below, books from favorite college classes under that, then the craft and design books I'm into now. Current fiction either goes straight into the hands of someone who will love it or to the Friends of the Library store.

by subject, then size and color

Other - I return them to the library.

By colour, looks cute and works for me. I mostly just have fiction though, that might be why it works.

Mehitabel- nice, very High Fidelity-ish.

i've got a shitload of books and they're all haphazardly stacked and double-rowed on my bookshelves. the only neat and orderly area is another bookshelf that holds my favorite poetry books and my brother's prized art books. everything else is rammed in wherever a spot can be had on our built-in shelves. we've got hundreds of yummy books, but i do know that soon i'll have to tackle 'em, sort 'em, sell some, organamize the rest. by subject, then author :) no color! it seems too contrived for me. books are beautiful without wearing makeup!

This just reminds me that it's time to shake my shelves up a little and do some re-positioning.

Mine are arranged according to an arcane personal method that makes sense to me. The "A-list" or favorite books are in my bedroom then sorted by category and/or author (all my Patrick Dennis; Rita Mae Brown; Christies; Robert Heinlein for example) . The spare room is where others live-- a lot of paperbacks; different series of mysteries and so on.

And jmorey's post about why people keep so many books gives me the perfect chance to use a quote I have framed on the bedroom shelves

"She had often noticed that when people with large libraries fall into trouble, the fact that the books had not risen en masse to help them always seemed to give those without books comfort" Amanda Cross--"Death in a Tenured Position"

By topic.

I dislike books-as-decor, which includes arranging them by color, turning them into tables, or displaying an impressive row of bound books that are never opened.

very nice quote

to the person who said that they think when people arrange by color it looks like they don't read them, why? i'm not defending color organization til the end, i just happened to do it this weekend and it looks good. It just seems like people are very negative towards color.

Maybe i'm more of a visual person then most. when i think of a book i need, i know what it looks like, i can look at the shelf and know exactly where it is because i know what color it is. this obviously won't worry in libraries since then you don't know what they would look like before you find them (most of the time).

Why can't your bookcase serve the function of holding the books you want to read and reference while be pleasing to the eye. i know what is pleasing is in the eye of the beholder. it just seems like there is a lot of color bashing.

I basically arrange all my books by subject - teaching books together, Bible studies, cookbooks, travel, novels, classics etc. I try to save space to put all my library books together so I dont have to hunt for them when its time to return them.

Mines are organized by height, color, and series.

I've got a couple different systems. First, I have my photography/design/art/travel/cook books on their own shelf. They're loosely arranged by size and like subject. Then I have a set of critics'/non-fiction books about movies, music, culture, etc. And I put my comics in another section. Finally, I've got fiction (with a sprinkling of poetry) divided into read (favorites) and to-read. Of the read books, I only keep the ones I love and would read again. All other read books are sold to Green Apple and Half Price Books, or donated to friends or Goodwill.
Last, I've still got a set of nostalgic childhood/youth books stored in Ikea storage boxes in my closet. I have this hidden nook that fits the boxes exactly.
I wish I didn't love books so much. I already stopped buying more fiction and pocketbooks some years ago, but there's still so much.

Fiction - of which I have probably only 80 or so - I arrange them alphabetically by author.

Nonfiction - which constitutes by far the bulk of my library - I arrange them in sections according to topic. Personally, I'd never be able to easily find anything if I did it by colour or by author alphabetically! Also, I like being able to easily scan/browse a range of books on one topic.

I also usually have a "quick reference" section for books I am currently reading. Depending on the space available, that may be a section of one of the bookshelves, or somewhere totally separate.

Subject

I have several book cases and each one houses a different subject like history, design and fiction. I then divide the books by color within that book case.

I have a hard time keeping books organized by anything but color, it's the only instant visual that cues me to put it back where I got it. If I tried to organize by anything else, they would end up in stacks to be "put away correctly" and then instead of color coordinated stacks i'd end up with non-color coordinated, non-anything stacks. I only have about 40 or so books so thats probably why this method is practical. To each his own!

The color thing drives me crazy!! i guess because it just seems that the person is treating their books as decoration--there's no substance in that. my books are all there because i am truly into them; anything that i don't truly want i sell on half.com or donate.

Also, I want to find them quickly for reference, so I organize by subject.

By category, in a personal way, how I will find them easiest.

Definitely by category!!

As a former barnes & noble employee--once upon a time, a long time ago :)--I'm pretty regimented about my bookcases...I have two huge cases in my study flanking my desk ....the right bookcase is fiction and the left non-fiction (for starters)....the fiction is split into subcategories (new fiction, series novels, shakespeare, jane austen&everything before her...and then poetry at the end, beginning with anthologies)...the left bookcase is segmented into subcategories: psychology, sociology, religion&spirituality, memoir, travel essays&guides, women's studies, health, and reference/writing on writing materials ....yeah i may be a little out of control but I love the order of it all, so easy to sort through and organizationally reminiscent of my b&n days :)!

...oh, and the fiction portion...within the subcategories is arranged by author alphabetically :)

I read them, then donate them. As much as I have been attached to my books in the past, if I'm not going to read it again, I pass it along to the library.

Personal category loosely based along the lines of a library-esque system. So, fiction's generally together, but sometimes not as others would arrange it. I've recently started cleaning out my collection though--and now, when I buy books (which I try not to do as much), I read and sell or read and donate.

I hated the color arrangement too...but then I helped my mom do some organization, and there, it made sense because there was so much going on on the shelves...when I rearranged the books by color, it really relieved some of the busy-ness.

I agree with kdkaboom's comment my husband and I have so many books that they're haphazardly arranged on our bookshelves double stacked. We put them wherever we can fit them for the most part.

The parts or our bookshelves that are organized we've tried to do by size, category, and try and put all the series and authors together as much as possible. We both like to read a lot and in between rereading some of our favorites, getting new ones (for review and for pleasure) and books to be read. It's one of those fantasy projects to be able to arrange our all our books in a coherent system. We've moved twice, so most are still in moving boxes.

I saw this really great book at a used bookstore called Living with Books. It's the best coffee table book I've seen so far that illustrates people with big libraries living among their books and not just using them as props.

Subject and size.

Mostly by subject; authors together; sometimes - fun or whimsical juxtiposition - i.e., Noel Coward books topped by Elements of Style

I have my books precisely arranged so that if I have a friend over, and I want to show him or her a book, I can always put my hand right on it five minutes after the friend has gone home. It's very exacting to maintain this system.

I basically arrange by genre, then country of author/subject (ie, section of fin de siecle Viennese works). But I also have a couple of favorite shelves which house books I currently feel great warmth for and have a strong urge to read or reread. This is the most infallible arrangement of all.

I just moved in with my boyfriend, and together we've got about 1800 books in our relatively small apartment. I had always organized by topic, then alphabetical by author within the topic. Unread books are kept separate, in a shelf by the door (for grabbing on the way to the bus). I also have a shelf of oversized, coffee table-type books that are primarily visual, even if they aren't technically art books (books of maps and so on). But the boyfriend wants to go Dewey decimal. He's done a few shelves and there are some weird transitions there. Things I would put in agriculture are in with the political books, and so on. There's a reason the big bookstores don't follow the Dewey decimal system - it's confusing. But my guy is also entering all the books into Librarything (an online personal library database), so at least we'll have a guide to what I am sure will be an ever-expanding collection. Frankly, being in houses with only one or two shelves of books depresses me.

For years and years, I shelved by genre then alphabetically by author within genre. As part of last year's Cure, I reshelved by color and I love it. I have upwards of 1000 paperbacks, and shuffling the order has made me think about them in new ways. When I think of a book I want to reread, I generally can call up the color as well as the title in my mind. If not, I browse my shelves to find it, often making mental notes along the way of other books to reread or to donate.

I don't consider my books props or decor; with the exceptions of new additions, they've all been read (often multiple times) and are loved because of the words inside not the color outside. That said, reordering my six bookcases by color has reduced the visual clutter on that wall which works for me since I have so much other stuff around creating visual clutter.

I find it interesting that many folks are so vocal about their opinions of those of us who arrange by color- no one has suggested that arranging by Dewey of LCC is pretentious or impractical. To each his own- as long as you can find what you are looking for, your system works for you; give other folks the benefit of the doubt that their systems work equally well for them.

Mostly by subject - cookbooks, house and home, novels (what we actually keep), art, reference etc. Once they are on the right shelf (or group of shelves) it is all up to how they look (height, shape, etc). Hope that helps!

Love your shelves by the way! Wish I had the doors to keep the dust at bay!

:)

By how much I like them. All the ones I wouldn't be without are grouped together--almost all paperbacks. And then I have a group of favored hardcovers, then it kind of devolves into books I enjoyed but wouldn't necessarily read again to ones I haven't yet read. It makes everything simple and intutitive to find (if you are me). And the less favored ones end up getting taken to the Strand.

1. By subject, first.

2. Then by author, if I'm dealing with a series.

3. Then by height, on each shelf. I hate having tall books in the middle of a range if I can help it. Tall books go on the ends of the shelf.

4. And finally, by use. Seldom used subjects get on the lower and upper shelves (of the taller bookcases), with heavy-use items in the middle, where they are more available.

4a. But if a subject has a lot of big, heavy books, it will tend go on a lower shelf no matter the usage-rate. My shelves are not fastened to the wall, so it's a consideration.

Just FYI, I'm a librarian. No Dewey or LC for me. I don't get paid to assign call numbers at home. :-)

When people arrange their books by color I think it looks like they don't actually read them, they just want them as a prop.

I have to disagree. This system works really well for visual people like myself. I used to arrange my books alphabetically by author but always got caught up in, for instance, a definitive book about one person but written by another, or author versus editor, or multiple authors. Breaking the alphabetical rule drove me nuts. Then, I tried a thematic arrangement but got lost in the overlapping nuances of so many of my books. Color is perfect for me!

By subject, for ease. After seeing so many color-coded bookshelves this year, I've eventually gotten caught up in the idea but I have just enough books to make it seem insanely impractical. Maybe the next time I dust them (Arizona, sigh) I will try to color organize within subjects, but then I know I will get hung up on book size! Fascinating to read people's different perspectives on what feels easiest to them.

Mine are "organised" so, that they look fun, different colors as random as possible in an eye-pleasing manner. Old books with new books, novels with dictionaries... and usually the prettiest books are on eye-level, ugliest on the bottom.

By subject. It's the easiest way to find a book and after working in libraries for years it seems odd any other way.

I work at home in a visual related field, and I sort by genre, then by different standards within the genre (history by date, travel by location, cooking by cuisine, etc.) but I'm pretty rigorous about height. I'd guess we have about 3000 to 3500 books, and yes, I do re-read them or refer to them all. I give away fiction, and try not to buy beach paperbacks. The books are my resources. Color would be fun, but how do you sort the Penguins?

I love seeing that people are as passionate about their books as I am...I tend to be judgmental when it comes to other's libraries. Its often times the first thing I want to scope out when going to someone else's home for the first time.

I, too, group my books by category. After that, I try to find attractive groupings by sub-category. I don't trust people whose shelved look too attractive. I hate books as decoration-if you haven't read them (or plan to read them) you shouldn't have them in your home! Its deceptive. I find bookshelves organized by color very telling...and I don't really like what it says.

Topically.

Everytime I think about sorting books by color I get hives.

They used to be roughly by subject area (books related to school, foreign-language, hard-cover fiction, hard-cover nonfiction, cookbooks) only, then within each area I ended up organizing them by color, because I got tired of how jumbled everything looks. I didn't think I'd like it (I do generally like them alphabetically), but my bookshelves do look a little more streamlined. I've staggered and interspersed books with other items so it doesn't look *too obvious.

First size, then author for fiction, and topics for non-fiction.

Sorting by color looks nice, but I don't think I'll ever do it to my own shelves, as I don't need a visual cue. I just *know* where my books are.

As for why some people have so many books?

See the Wiki-entry on "Bibliophily":

"The classic bibliophile is one who loves to read, admire and collect books, often nurturing a large and specialised collection."

Also for those who fit in the above description:
At Home With Books. Booklovers and their private libraries. Highly recommended. (Just ordered it. ^^)

Mine really aren't arranged by any method other than how I can get them on my shelves neatly, though my art books are arranged by color. In general, I get rid of old books and purchase new ones too often to have a set system. I'd have to rearrange everything too much because my literary tastes or interests are always changing. I have a good enough memory and a small enough library to find my books easily enough.

By purpose. Everything that pertains to my writing one shelf, everything that pertains to my art five shelves, and so on.

by affection.

By size first (hardbacks vs. paperbacks vs. trade paperbacks), then by type (fiction, nonfiction, SF, animals, etc) then by author.

It depends on the size of the collection.

I don't keep many books in my room (since I only have space for a tiny bookshelf - I know, I know!) and the rest are in the family shelves outside, but the ones I do keep in here are sorted by genre, then, generally size. Doctor Who books (...I have a lot of those!) are series / chronological - the Target paperback novelisations are the oldest, so they go together (in order of serial), then all the BBC releases, then the more recent ones. Science books go by size, although since he's my favourite writer, I keep my Carl Sagan books seperate (but sorted by size amongst themselves).